Luminal obstructive symptoms such as dysphagia, vomitus, jaundice, or ileus are often the first symptoms noticed by patients or physicians and unfortunately, usually indicate an advanced stage of gastrointestinal disease associated with high mortality. Stenting of malignant biliary obstructions, performed on patients who are not candidates for curative surgery, is currently performed as palliative treatment with limited success. These stents fail one third of the time due to tumor growth through the struts of the stent. Our efforts will be focused on optimizing an iridium-192 radiation source for low dose rate permanent brachytherapy. This medical device would reduce costs and improve quality of life for the patient, because it requires only one intervention compared to other methods of palliative radiotherapy (HDR, EBRT), which require daily treatment regimens, often for weeks at a time. In addition, unlike EBRT, the dose to radiosensitive nontargeted tissue is greatly reduced. The proposed iridium-192 stent also has greatly improved radioopacity for enhancing accurate placement. [unreadable] [unreadable] [unreadable]